Researcher from the University of Texas participates in the Charles Darwin Seminars

By Emerson José

Researcher Kelly Zamudio presented the lecture “Diversification and Conservation of Neotropical Amphibians” last Tuesday (21st) as part of the Charles Darwin Seminars. The event, an initiative of CBioClima, was held in the library auditorium at Unesp in Rio Claro. Kelly is a world-renowned expert in evolutionary biology and the conservation of Neotropical amphibians and is a professor at the University of Texas at Austin (USA).

Kelly began her lecture by discussing the diversification mechanisms of amphibians and the ecology of infectious diseases. One key point she highlighted was how toads avoid risky crosses and what this teaches us about amphibian conservation.

According to the researcher, "in Neotropical forests, hybrid zones—areas where two distinct species or populations meet and breed—function as 'natural laboratories' for understanding how new species emerge and how the boundaries between them are maintained. In a recent study with frog species from the Atlantic Forest, researchers discovered that, instead of seeking genetically different partners, amphibians prefer to mate with genetically closer individuals—a behavior known as 'outbreeding avoidance'."

This pattern was observed in two frog populations (Caraguatatuba and Picinguaba). The choice for genetically similar partners may be a strategy to avoid "outbreeding depression," a phenomenon that occurs when crossbreeding between very different lineages reduces the offspring's adaptation to the local environment.

Another point frequently mentioned by the professor was a threat that endangers the survival of hundreds of amphibian species: the fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Recent studies show that Bd has contributed to the decline of at least 501 amphibian species in recent decades, 90 of which are extinct or presumed extinct in the wild.

To predict and combat susceptibility to disease, scientists are turning to an innovative technique: museomics. By sequencing DNA extracted from museum specimens—some collected as far back as the 1940s—it is possible to compare genetic diversity before and after the population decline caused by Bd.

These findings reinforce the importance of integrating behavioral, genomic, and historical studies to understand—and reverse—the biodiversity crisis affecting amphibians on a global scale.

The full lecture will soon be available on the CBioClima YouTube channel. The next Charles Darwin Seminar will be on December 2nd, Tuesday, at 1 PM, featuring researcher Fernanda Abra, in the IB auditorium.